Stumbling and Sniffing Wireless Networks in Linux, Part 2

Stumbling (and Managing) with KwiFiManager

October 26, 2009

By
Eric Geier

Last week, we started a tutorial series on stumbling and sniffing networks in
Linux. First we reviewed some general stumbling and sniffing information. Then
we looked at a NetStumbler look-a-like, SWScanner.

Now we'll continue stumbling with KwiFiManager; which can also serve as your
wireless connection manger. Then we'll start sniffing with tcpdump, a command-line utility.

Stumbling (and managing) with KwiFiManager

If you regularly need to scan the airwaves for APs and networks, you might
consider using KwiFiManager.
It not only includes some stumbling and surveying features, but it lets you
manage your Wi-Fi connections. This might not be the right tool for a full
survey, but it's convenient for quick scans. Since it serves as your wireless
manager, stumbling is always one click away.

Once you install and run KwiFiManager, its icon showing the signal bars and
value for the current connection appears in the system tray. To open the
application, click the icon. The details for the current connection is shown on
the main screen, as you see in Figure 2. This includes the channel, data rate,
MAC address of the AP, and your assigned IP address.

Figure 1: KwiFiManager's main screen shows the details of your current
wireless connection.

The main screen also sports a set of signal bars and the signal value. Though
this is not the dBm value, a preferable measurement for surveying, its shows an
effective signal level, the 'Quality' value. Either your wireless card will
report this Quality value or it will be calculated by subtracting the noise
level from the signal strength in dBm. However in some cases, the card won't
report the Quality value, it will simply be the signal strength. To force
KwiFiManager to calculate it, click Settings > Use Alternative Strength
Calculation.

When you want to do some stumbling, click the Scan for Networks button. This
pops up a window that shows the network names, modes, signal quality values, and
encryption statuses for each AP picked up. If you want to actually connect to a
network, select it from the list and click the Switch to Network button.

Two other surveying features are available from the Settings menu on the
toolbar of the main KwiFiManager screen. To view a live graph (see Figure 2) of
the signal and noise levels of your current connection, click Statistics. This
is great for when troubleshooting connectivity issues or determining AP
placement. KwiFiManager can also help you track down rogue or forgotten APs.
From the Settings menu, you can also bring up the detector feature. When
enabled, you'll hear beeping which gets louder and quicker as you get closer to
the AP.

figure 2

Figure 2: You can monitor the signal and noise levels of your current Wi-Fi
connection with KwiFiManager.